Work is proposed on a variety of projects on reovirus, vaccinia virus, RNA tumor viruses and interferon. Among the projects to be investigated are: Sequencing (by determining the 3'-terminal sequences of their component plus and minus strands) the L3, M3 and S2 genes of reovirus serotype 1, 2 and 3; cloning reovirus genes by ligating primers to the 3'-termini of plus strands and transcribing them into cDNA, and then sequencing the cloned genes; determining how genetic relatedness is distributed among the genes of the three serotypes of reovirus, by measuring the extent of single-strandedness of heterologous ds RNA hybrids of serotypes 1, 2 and 3; using a series of hybridoma-produced antibodies directed against various reovirus-specified proteins to construct a morphogenetic pathway of reovirus, with particular emphasis on the nature of the most immature reovirus particles in which ten distinct species of RNA are assembled and transcribed; to clone mouse interferon genes using significantly enriched mouse interferon messenger RNA preparations, and to use such cloned mouse interferon genes for the cloning of human interferon genes; to determine the effect of phosphorylation on the catalytic properties of the avian sarcoma virus reverse transcriptase (by examining the activity of this enzyme in its dephosphorylated and rephosphorylated state), and to determine when during virus morphogenesis the beta subunit of the reverse transcriptase is phosphorylated; to clone vaccinia DNA, in particular its terminal regions, and to sequence them in order to identify signals that specify initiation and termination of DNA replication, as well as the signals that specify the generation of deletions; to clone vaccinia virus DNA in approximately double gene size fragments (M.W. about 3 million) and to prepare a gene map of vaccinia DNA by coupled transcription-translation of the cloned segments in in vitro systems, or by using cloned segments to isolate messenger RNA species transcribed at various stages of the multiplication cycle.